A genuine steering wheel (standard specification) that is mounted on a vehicle or the like is replaced with another steering wheel (other than the standard specification) other than the genuine steering wheel as necessary for user preferences or the like in some cases. When the genuine steering wheel is replaced with the other steering wheel, a switch (for example, an operating switch of a stereo system, an air conditioner, a car navigation system, or the like) that is mounted on the genuine steering wheel is also detached along with the genuine steering wheel. This degrades user convenience. Hence, even in a case of using the other steering wheel, it is desirable to be able to reuse the switch that is mounted on the genuine steering wheel.